The Affordable Care Act has been dramatically changing the way hospitals do business, forcing them to rethink which patients they admit and focus on keeping people healthy. For Kaiser Permanente, however, it's been largely business as usual, says CEO Bernard Tyson, who took the helm a year ago. Kaiser is a fully integrated hospital-doctor-insurance company, kind of an "accountable care organization" on steroids. ACOs are networks of doctors and hospitals that share financial and medical responsibility for patients' care — exactly what the ACA encourages with Medicare, using bonuses for efficient and effective health care.